diff --git a/ChangeLog b/ChangeLog
index 636f0ac33f..7c064e7bcd 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Thu Jul 28 14:25:08 2011  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* lib/rubygems/user_interaction.rb (Gem::StreamUI#tty?): typo.
+
 Thu Jul 28 12:32:53 2011  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* ext/dl/callback/mkcallback.rb (gencallback): use PTR2NUM.
diff --git a/lib/rubygems/user_interaction.rb b/lib/rubygems/user_interaction.rb
index df51326c01..8024d37287 100644
--- a/lib/rubygems/user_interaction.rb
+++ b/lib/rubygems/user_interaction.rb
@@ -136,7 +136,7 @@ class Gem::StreamUI
   end
 
   def tty?
-    if RUBY_VERSION > '1.9.3' and RUBY_PLATFORM =~ /mingw|mswin/ then
+    if RUBY_VERSION < '1.9.3' and RUBY_PLATFORM =~ /mingw|mswin/ then
       @usetty
     else
       @usetty && @ins.tty?